Could you help me clean up a bit the standard PRS-T1 ebook viewer for periodicals?

I didn't like that when I open a periodical a big portion of the lower screen is dedicated to showing an empty bar with the button "Table of Contents". It's ugly. So I changed the layout.xml. I moved the button to the section bar, but.... Now where the ugly bar was now there's an empty black space (see screenshot), and for my life I can't seem to get rid of it.

I've been trying to remove it by giving things visibility "gone" here and there, but after of more than an hour of blindly poking I think I've run out of options (I'm an absolute newbie of Android tinkering) and I come here hoping that some of you can give me a hand or point me to the right direction